This application claims benefit of priority under 35 USC xc2xa7119 to Japanese Patent Application No.P2000-238948, filed on Aug. 7, 2000, the entire contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to a stencil printing machine and a control method thereof having a plurality of printing drums capable of performing multi-color printing.
2. Description of the Related Art
In general, a stencil printing machine having plural printing drums capable of performing mono-color and multi-color printing comprises a first printing drum 111a, a second printing drum 111b, and a pressure drum 112 which are arranged rotatably, as shown in FIG. 1. Each of the first and second printing drums 111a and 111b are placed closely at the outer peripheral surface of the pressure drum 112 separated to each other in approximately a 90 degree angle around the center of the pressure drum 112.
In the initiation of the stencil printing process, firstly, stencil sheet clamp sections of both the first and second printing drums 111a and 111b clamp corresponding stencil sheets having perforations made based on the first and second color printing data so that they are rolled on the outer peripheral surface of the corresponding printing drums. Following this process, a print paper is fed between the first printing drum 111a and the pressure drum 112 from the paper feed section 113 while the first and second printing drums 111a and 111b rotate around the arrow A in synchronization of the rotation of the pressure drum 112 around the arrow B.
Thereby, a print paper clamp section in the pressure drum 112 clamps the print paper which is fed and whereby the paper is further fed between the first printing drum 111a and the pressure drum 112 through the outer peripheral surface of the pressure drum 112. At this time, a first color ink is transferred onto the print paper through perforations made in the stencil sheet.
Next, the print paper from the first printing drum 111a is fed between the second printing drum 111b and the pressure drum 112. Similar to the first color printing process described above, the second color ink is transferred to the print paper through perforations made in the stencil sheet rolled on the second printing drum 111b. A paper delivery section 114 then delivers to a predetermined position the print paper on which a desired printing image data has been printed. Finally, the stencil sheets rolled on the outer peripheral surface of the printing drums 111a and 111b are disposed into discharged stencil sheet boxes 115a and 115b. Thereby, a series of the stencil printing process is completed.
By the way, the stencil printing machine of the configuration described above has a drawback in which the entire printing process, specifically, a mono-color printing process can not be performed when one of printing drums is not mounted in the machine, or no ink cartridge is mounted, or the ink cartridge is empty, or no discharged stencil sheet box is mounted, or the discharged stencil sheet box is filled in one of the printing drums. In those cases, it is hard for the user to handle the stencil printing machine having the above configuration, specifically, in order to perform a mono-color printing.
Accordingly, an object of the present invention is, with due consideration to the drawbacks of the conventional technique, to provide a stencil printing machine and a control method thereof capable of improving the user-handling of the stencil printing machine and the stencil printing process.
In accordance with an embodiment of the present invention, a stencil printing machine comprises a plurality of printing drums and a control section controlling a stencil printing process so that even if the printing drum that is not used in the current stencil printing process is in an error state, the stencil printing process is performed by using other printing drums. By this configuration of the stencil printing machine, it is possible to perform the stencil printing process using the printing drum which the user selects in the process without causing any trouble even if one printing drum which is not used in the process is in the error state.
Furthermore, in accordance with another embodiment of the present invention, a control method of a stencil printing machine having a plurality of printing drums comprises a control step of controlling a stencil printing process. In the control step, even if the printing drum that is not used in the current stencil printing process is in an error state, the stencil printing process is performed by using other printing drums. By this control method, it is possible to perform the stencil printing process using the printing drum which the user selects in the process without causing any trouble even if one printing drum which is not used in the process is in the error state.
Moreover, in accordance with another embodiment of the present invention, a control method of a stencil printing machine having a plurality of printing drums capable of performing mono-color and multi-color printing processes comprises a control step in which a stencil printing process is so controlled that even if the printing drum which is not used in an error state, the mono-color printing process is performed by using other printing drums. By this control method, even if the printing drum that is not used is in the error state, it is possible to perform the mono-color printing process by using other printing drums.
The stencil printing machine described above comprises a printing drum absence detection section comprising detectors provided to a corresponding printing drum detecting whether or not each of the printing drums is mounted in the stencil printing machine, a discharged stencil sheet box absence detection section comprising detectors provided to a corresponding printing drum detecting whether or not the discharged stencil sheet box is mounted in the corresponding printing drum, and a discharged stencil sheet box full detection section comprising detectors provided to a corresponding discharged stencil sheet box detecting whether or not the discharged stencil sheet box is filled with used stencil sheets. In addition, each printing drum further comprises an ink container detection section detecting whether or not the ink container is mounted in the corresponding printing drum, and an ink sensor section detecting whether or not an ink is filled in the corresponding ink container in the printing drum. In the stencil printing machine, the control section controls the stencil printing process based on detection results of the above detection sections.
Furthermore, the stencil printing machine described above further comprises an operation panel displaying error information and through which a user selects one or more of the printing drums to be used in the stencil printing process and instructs to initiate the stencil printing process. In the stencil printing machine, the operation panel comprises at least one of the display sections to inform the following error states for each printing drum to the user: no printing drum is mounted; no ink container is mounted; ink container is empty; no discharged stencil sheet box is mounted; and a discharged stencil sheet box is filled with discharged stencil sheets.